I think names like Maegan and Maeson are annoying, but not necessarily names that just start with the same letter...more of those that actually sound alike. Both of my girls start with an A...it was not intentional and they don't sound alike. It does start to bother me when there are several kids (Duggar style), or the entire family. We have friends that the mom, dad, son and their last name all start with the same letter...J______, J______ & J________ J_______. That bothers me too.
This was my family growing up all J lastname
I had no plan to use all M first names, but once we chose Maeve after Moira we agreed if we had a 3rd girl she would have to have a M name too, mainly to not feel left out. FWIW, our boy choice did not start w/M